Onesimus (late 1600s–1700s) was an African-born man held as a slave by Puritan minister Cotton Mather, who helped mitigate the impact of a smallpox outbreak in Boston by introducing Mather to the principle of inoculation. In a 2016 Boston Magazine survey, he was declared one of the "Best Bostonians of All Time".
Biography
Onesimus' place of birth is not known with certainty. Mather referred to his ethnicity as "Guaramantee", which is most likely Coromantee, people of Ashanti or Akan descent. He was brought to North America as a slave, and given into Mather's custody by the preacher's congregation in December 1706. Mather named him after a first-century CE slave mentioned in the Bible.
In 1716 or shortly before, Onesimus described to Mather the process of inoculation that had been performed on him and others in his society in Africa (as Mather reported in a letter): "People take Juice of Small-Pox; and Cutty-skin, and Putt in a Drop." When Boston experienced a smallpox outbreak in 1721, Mather promoted inoculation as protection against it. However, he cited Onesimus and his people as the source of the procedure, which led to resistance from those suspicious of African medicine. Nonetheless, a physician carried out the method Onesimus had described on 242 patients, a population which experienced only 6 deaths, compared to 844 deaths among the 5,889 non-inoculated smallpox patients.
In 1721, Onesimus attempted to purchase his freedom from Mather, raising funds to purchase another enslaved man to take his place. Mather had grown unhappy with Onesimus (who had resisted conversion to Christianity), and suspected him of theft, and thus placed conditions on his release.